With the need for reducing costs or times associated with business trips, more companies are moving towards transmission systems to have teleconference or videoconference among remotely located offices via a communication network. The transmission systems allow transmission of contents data such as image data and/or voice data among a plurality of transmission terminals that are remotely located from one another through the communication network such as a leased line and/or the Internet to facilitate communication among the plurality of transmission terminals.
While the Internet is widely used for the communication network as it is cost-effective, contents data may not be safely communicated through the Internet, for example, due to inappropriate settings of a router on the Internet. Further, since the band used for data communication tends to be unstable on the Internet, it has been difficult to keep the quality of image data or voice data to a certain level. In any case, the transmission systems may not be able to start communication, or communication being carried out by the transmission systems may be interrupted. When communication is interrupted, the user at the transmission terminal usually contacts an administrator of the transmission systems by other communication means, such as telephone or email, to ask for a solution to fix the problem. This requires substantial time before communication is resumed.
Japanese Patent Application Publication No. H7-162825 describes a system that monitors the communication line and each terminal unit, and upon detecting a fault, the system stores fault information regarding the detected fault. Further, when the detected fault is a heavy fault that may interrupt communication, the system calls a registered service office to notify of its fault conditions.